Effects Of A20 On TLR2,4-p38MAPK/NF-?B Signaling Pathways And Clinical Phenotypes In Mouse Models Of Systemic Lupus Erythematosus

Background:SLE(Systemic Lupus Erythematosus,SLE)is a typical autoimmune disease,the body system more organs are affected,more complex clinical manifestations of the disease,illnesses out repeatedly,is its pathological features in a variety of autoantibodies and the formation and deposition of immune complex,which can lead to severe inflammation and tissue damage,cause airframe multiple target tissue damage and exhibit a variety of corresponding clinical symptoms and signs.A20 is the zinc finger protein encoded by the TNFAIP3(Tumor Necrosis factor Alpha Induced protein 3)gene.Genome-wide association and candidate gene studies have shown that TNFAIP3(A20)is a susceptibility gene of SLE,and abnormal A20 expression is closely related to the pathogenesis of SLE,suggesting that this gene plays an important role in the regulation of SLE autoimmune inflammatory response.p38MAPK and NF-?B play an important role in autoimmunity,inflammation and apoptosis.After activation,they can induce the expression of large amounts of inflammatory cytokines such as IL-6 and TNF-?,causing inflammation in the body.A20 negatively regulates the activity of p38MAPK and NF-?B pathways,such as toll-like receptor(TLRs)-activated p38MAPK and NF-?B receptors,of which A20 inhibits ubiquitination and deubiquitination.The study found that THE expression of TLR2 and 4 in PBMC of SLE patients was significantly higher than that of healthy people,suggesting that TLR2 and 4 play a non-negligible role in the regulation of SLE inflammatory response.Therefore,abnormal A20 expression may further induce persistent inflammatory response and tissue damage in SLE by regulating the activity of TLR2 and 4-p38MAPK/NF-?B signaling pathways.Purpose:Whether TLR2 and 4-p38MAPK/NF-vB signaling pathways are actively involved in the pathogenesis of SLE;To investigate whether high expression of A20 alleviates disease in mice with systemic lupus erythematosus(SLE)by regulating TLR2 and 4-p38MAPK/NF-?B signaling pathways.Methods:MRL/lpr and BALB/C female mice aged 4-5 weeks were randomly divided into BALB/C negative control group(Sham;n=18)and untreated MRL/lpr mice(SLE;n=18),MRL/lpr mice Daphnetin treatment group(Daphnetin;n=18).The changes of hair and body weight and survival rate were observed during administration.After the administration,the urine protein was measured by Coomassie bright blue method and the blood urea nitrogen level was detected by the kit.Serum anti-DNA IgG,IL-6 and TNF-alevels were detected by Elisa.Protein expression levels of A20,TLR2,TLR4,pp38MAPK and pNFKB-p65 in peripheral blood mononuclear cells were detected by Western Blot.Chi-square test was used to compare the survival rate of mice in the three groups and one-way ANOVA was used to calculate the difference between the groups.The results were mean ± standard deviation(x±s).Results:After Daphnetin treatment,A20 expression was significantly up-regulated in Daphnetin group compared with SLE group,while there was no significant difference in A20 expression between SLE group and negative control group.Western blot also showed that the protein expression levels of TLR2,TLR4,pp38MAPK and pNF?B-p65 in SLE group were significantly increased compared with the negative control group,while the protein expression levels of TLR2,TLR4,pp38MAPK and pNF?B-p65 in Daphnetin group were significantly decreased.Elisa results showed that the levels of IL-6 and TNF-?in SLE group were significantly increased compared with the negative control group.The levels of IL-6 and TNF-?in Daphnetin group were significantly down-regulated compared with SLE group.Secondly,detection of serum anti-DNA IgG,blood urea nitrogen and 24-hour urinary albumin in mice showed that SLE group was significantly higher than the negative control group,and serum anti-DNA IgG,blood urea nitrogen and 24-hour urinary albumin in Daphnetin group were significantly lower than SLE group.In addition,from the general situation of mice,mice in SLE group were thin in appearance,with messy,shed,dry and dull hair,while mice in Daphnetin group were in good condition,with smooth,shiny hair and no obvious shed in the negative control group.During the experiment,6 mice died in SLE group,2 mice in Daphnetin group and none in negative control group.Conclusion:TLR2 and 4-P38MAPK/NF-?B signaling pathways are actively involved in the pathogenesis of sle.Highly expressed A20 has protective effect on lupus model mice.High expression of A20 may be one of the mechanisms of SLE remission by inhibiting TLR2 and 4-p38MAPK/NF-?B signaling pathways.